Executive Editor: Peter Trafton

Authors: Keith Mayo, Michel Oransky, Pol Rommens, Carlos Sancineto

Acetabulum - Both column fractures with extended iliofemoral

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Glossary

1 Fracture anatomy top

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Both-column fractures are formed by the association of two elementary fractures, the posterior column, and the anterior column fractures. The level of the posterior column fracture may vary.
No part of the joint surface remains attached to the stable proximal part of the iliac wing.
The anterior column fracture line reaches the top of the crest at a level varying from the anterior superior iliac spine to the most posterior portion of the iliac wing.
Most of the acetabular roof stays with the anterior column fragments.
Associated fracture lines in comminuted fractures may create more complex patterns.
Type I (Letournel)
In type I both-column fractures, per Letournel,  the anterior column fracture line crosses the iliac crest, as shown in this illustration.


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Type II (Letournel)
In type II both-column fractures, the anterior column fracture line exits through the anterior portion of the iliac wing, at variable levels.
As in type I fractures, the posterior column fracture may be comminuted and/or at different levels.


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Type II (Letournel)

2 Fracture reduction top

Reduction strategies

The goals for ORIF of acetabular fractures are to achieve a perfectly congruent reduction of the articular surface of the hip joint, and to stabilize it sufficiently for healing with maintenance of reduction, while allowing range of motion for the injured joint. The early care of the patient involves prompt closed reduction of significant displacement, particularly hip dislocation. Surgical reduction becomes more difficult with delay, so that definitive treatment must be done as soon as safe and practicable.

Careful planning is essential. This requires assessment of the entire patient, recognition of and appropriate treatment for other injuries, as well as focus on the acetabular fracture. With regard to the acetabulum, high quality images must be obtained and analyzed. The fracture must be interpreted and classified, and detailed step-by-step plans for surgical approach, reduction, and fixation must be formulated. If this can not be carried out where the patient is initially seen and resuscitated, arrangements for timely transfer to an appropriate center are essential.

Reduction of an acetabular fracture usually involves traction on the femur to reposition the femoral head, and free articular fragments. Such traction may aid visualization of the joint surface, which may also require dislocation of the joint. However, many acetabular fractures are reduced indirectly, by extraarticular manipulation of fracture fragments, controlled by the reduction of the nonarticular bony surfaces, and intraoperative x-rays, rather than by direct visualization of the joint itself. Traction can be applied with a special fracture table, a femoral distractor, or manually, with bone hooks or threaded pins as handles on the femur or major fragments. Individual fragment reduction is achieved with direct manipulation using threaded pins or clamps as handles on the fragments, and clamps, screws, or plates to stabilize and compress interfragmentary reduction. One must plan stepwise reduction and fixation of these frequently multifragmentary fractures. Frequently, combinations of reduction aids and fixation devices must be used.


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Joint distraction

Traction can be applied across the hip joint in several ways:

  • with a fracture table that allows axial and lateral traction
  • with a femoral distractor
  • with manual traction on the affected femur, with a proximal bone hook or Schanz screw to pull laterally, and manually on the leg for distal traction.

Note
Excessive axial or lateral traction through the fracture table may result in the locking of the fracture which makes further reduction impossible or difficult. The position of the femur may affect reduction and visualization. Thus it must be easy to adjust the traction and the limb position intraoperatively.


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Traction

Traction must be applied from laterally, to extract the femoral head from the pelvis, and to apply ligamentotaxis to medially displaced fracture fragments. Typically, axial traction is helpful, as well, to correct proximal displacement.
Both these forces should be tuned until the best effect is obtained.
A fracture table, typically with a trochanteric Schanz screw, is well suited for this.
If using a femoral distractor, additional lateral traction may be required, and care must be taken to position the distractor pins for optimal benefit.
Place the proximal pin into the sacroiliac (SI) region (as with the SI screw fixation), probably into the S1 body. Take great care to verify the position by fluoroscopy and by palpation through the greater sciatic notch.
Insert the distal pin through the lateral femur just distal to the lesser trochanter.
Once the desired femoral head position and fracture fragment location is achieved, start the definitive manipulative reduction.

3 Reduction of posterior column top

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Reduction of posterior column fracture

Reduction usually should start from the posterior column. The main principle is to lateralize the joint, closing the gap among the fracture fragments. This is begun with lateral traction as mentioned above. The goal is to reduce the posterior column  to the stable proximal ilium (spur fragment).
Usually the major distal posterior column fragment requires additional manipulation, with a bone hook on its medial edge, and/or a Schanz screw in the ischial tuberosity. Its reduction can be stabilized with clamps or a small plate across the fracture line between this fragment and the stable posterior ilium. Interfragmentary compression is important.
This illustration demonstrates adjustment of the posterior column with a bone hook while a Farabeuf clamp is tightened against two screws, one in the stable proximal fragment, and the other in the posterior column fragment. Screw position is important for optimal reduction. Another possibility is to use a pointed reduction forceps across the fracture, or a Jungbluth clamp.
The bone hook is placed into the lesser, or, as an alternative, the greater sciatic notch and pulled laterally to reduce the posterior column. Take great care not to damage the sciatic nerve. While the hook applies the force from medial to lateral, the clamp will close the fracture line and derotate the posterior column fragment.


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Special case: fractures separating the sciatic notch

In rare cases, a fracture fragment will include the sciatic notch, and enter the sacroiliac joint. These fractures are difficult if not impossible to reduce through an ilioinguinal approach, and should be approached with an extended iliofemoral incision.
For these fractures, one should begin with  anatomical reduction and fixation of the sacroiliac joint, and the greater sciatic notch fragment.
The next steps will be the reduction and fixation of the posterior column.

4 Fixation of the posterior column top

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Lag screw fixation

Fix the reduced posterior column with a 3.5 mm interfragmentary axial screw.
The screw orientation will vary depending on the obliquity of the fracture line.
The starting point for the insertion of the screw is located in the “spur” area of the stable proximal ilium.
This screw should not interfere with the desired position of the posterior column plate that will be applied later.

Note
A posterior column plate could be applied as a next step but usually is done later in the process of reduction and fixation, depending on the fracture pattern(reduction and fixation of an additional posterior wall fragment and/or an anterior column fragment etc.).

5 Reduction & fixation of posterior wall fragment top

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Reduction

The posterior wall fragment, when present, is located in between the fracture lines of the both column fracture. Its configuration, shape, and extension can vary.
Reduction will be more difficult when the fragment extends proximally in direction of the iliac crest and forms a fracture line parallel to that of the anterior column.
It is important that the fragment remains anatomically positioned between posterior and anterior columns, without gaps or step-offs of the joint surface.
In case of a difficult delayed fracture, it may be difficult to achieve a completely anatomical reduction. The emphasis should be on an anatomical joint surface reduction with “secondary congruence” of the fracture fragments.


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Fixation

The posterior column lag screw is in place. The illustration shows initial fixation of the posterior wall fragment with a 3.5 mm lag screw. Another screw or two may be needed. The fragment is held in position with clamps, rarely K-wires, while lag screws are placed.
Leave room for subsequent plate fixation.

6 Reduction and fixation of anterior column top

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Reduction of iliac crest

Start reduction from the proximal aspect of the iliac wing. Reduce the accessory fragment of the iliac wing, if present.
Reduction should not allow steps or wedge opening of the fracture line on the outer aspect of the crest.
Apply a pointed reduction forceps onto the iliac crest as a reduction aid and for temporarily fixation.
Alternatively, apply a Farabeuf or Jungbluth clamp over screws placed into the crest on each side of the fracture.


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Derotation and alignment of the anterior column

To reduce the anterior column, it should first be derotated with help of a Farabeuf clamp or a Schanz screw or a in the interspinous notch. The complete derotation and reduction is obtained with an asymmetric clamp.
Fine-tune the reduction with the  use of a Farabeuf clamp or a second reduction forceps applied over screws to the outer surface. This clamp will be able to approximate and slide the mobile fragment until the desired position is reached.
Remember that the goal is anatomical articular surface reduction.


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Reduction with intrapelvic clamp

If indicated, additional internal or medial aspect exposure of the iliac wing through the interspinous notch or through the crest will allow the application of an asymmetric reduction clamp to complete the derotation and reposition of the anterior column with respect to the stable iliac wing fragment. Another clamp or Schanz screw in the anterior column fragment will aid this reduction.


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This photo demonstrates reduction of the anterior column of a both-column fracture through an extended iliofemoral incision. The iliac wing has been reconstructed with lag screws and a plate stabilizing the free segment. A Jungbluth clamp holds the anterior column at the iliac crest. The anterior column reduction is adjusted with the Farabeuf clamp in the surgeon’s right hand while the asymmetric reduction clamp stabilizes the anterior column prior to definitive fixation.


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Iliac wing fixation

Initial fixation of the iliac wing and anterior column begins with the iliac crest. This is reduced and fixed with interfragmentary 3.5 mm lag screws, 3.5 mm low profile pelvic reconstruction plates, or with a combination of these implants.


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After provisional or even definitive fixation of the crest, it is possible to adjust the deeper portions of the anterior column. Thus, final alignment and periarticular fixation are the essential final steps of anterior column reduction and fixation.


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Anterior column screw

Further fixation of the anterior column to the distal part of the pubis can also achieved through lag screws that run from the medius gluteal pillar to the pubis (depending on fracture configuration and necessity.)
One or two 3.5 mm lag screws are used to stabilize the inferior part of the anterior column fracture.
As starting point, proceed 3-4 cm posterior to the AIIS and 2.5 cm from the acetabular rim.
For the correct direction, use the index finger along the pubic ramus and try to target it with the drill bit.
The correct inclination and direction of the screw must be confirmed with fluoroscopic imaging (modified Judet views).
Take great care not to penetrate the hip joint.
Use an oscillating drill and progress slowly. Remember that the external iliac vessels lie immediately adjacent to the superior pubic ramus.

7 Definitive fixation of the posterior column and wall top

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Application of a neutralization plate

A straight 3.5 mm low profile acetabular plate is contoured to fit the posterior column and wall. A length of six to ten holes is usually needed. It should be contoured to fit in its intended location.
The most distal hole of the plate should rest at the base of the ischium.
Aim the first screw through this hole, so that it travels through the ischium for a length of 40-60 mm. The direction of the plate and its end point will vary depending on the fragments to be fixed, usually close to the gluteus medius pillar.


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Another option, especially when a posterior wall fragment is present, is to apply a plate that starts from the ischial tuberosity and ends with at least two holes in the anterior column.

Note
When the plate is positioned close to the acetabular rim, the risk of joint penetration is increased.

8 Reduction and fixation of the anterior wall fragment top

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The anterior column fracture may present an independent anterior wall fragment. This has to be reduced and fixed to prevent anterior dislocation of the femoral head.
Through the extended iliofemoral approach, such anterior wall fragments are usually fixed with an anterior column interfragmentary screw, inserted from the lateral ilium.
Care must be taken to insure that this lag screw is inserted perpendicular to the anterior column primary fracture plane. Secondary displacement will occur with screw tightening if the screw crosses the fracture line obliquely.
The starting point for these screws is in an area of the innominate bone 2-3 cm cranial to the joint margin along the posterior margin of the gluteus medius pillar.
For the correct direction, use the index finger along the pubic ramus and try to target it with the drill bit.
The correct inclination and direction of the screw must be confirmed with fluoroscopic imaging (modified Judet views).
Take great care not to penetrate the hip joint.
Use an oscillating drill and progress slowly. Remember that the external iliac vessels lie immediately adjacent to the superior pubic ramus.
A small plate might be used for additional stability of the lateral fracture line.

v1.0 2007-07-22